基于性态的液化危险性估计  

Performance-based liquefaction hazard evaluation

作　　者：符圣聪[1] 江静贝[1] 黄世敏[1] 

机构地区：[1]中国建筑科学研究院建研科技股份有限公司,北京100013

出　　处：《建筑结构》2011年第11期22-27,130,共7页Building Structure

摘　　要：利用地震事件出现概率及给定地震事件的液化条件概率可估计液化的危险性。液化条件概率由binary-logistic模型对液化和未液化历史情况的基本数据进行回归分析确定;给定地震事件出现概率来自常规的地震动危险性的概率分析。基于性态地震工程理念,将液化安全系数和标准贯入锤击数(SPT)分别作为工程需求参数,计算特定场址液化概率。计算结果可用液化安全系数或液化需求锤击数的危险曲线来表示。基于性态的液化危险性估计途径可能比常规的方法更合理和一致地预测不同地震区场址出现液化的可能性。应用上述方法对北京地区不同地段各种设定土层情况进行液化危险性分析,分别得到了液化危险曲线。为便于工程应用,根据上述分析得到的大量样本及液化标准贯入锤击数基准值概念和土层埋深水位影响系数,提出了北京地区液化危险性评估的简化方法。相信其他地震区采用类同的方法也会得到适合该地区的液化危险性分析结果。The liquefaction condition probability of given seismic event and the annual probability of a seismic event are used to estimate liquefaction hazard at a specific site.The liquefaction condition probability is derived by the method of binary-logistic regression to analyze the database of field case histories of liquefaction and nonliquefaction occurrences.The annual probability of a seismic event is given by conventional earthquake hazard analysis.According to the conception of performance-based earthquake engineering,the factor of safety against liquefaction and penetration resistance are respectively adopted as a demand parameter for evaluation of liquefaction potential.The results can be expressed by hazard curves for factor of safety against liquefaction or demand penetration resistance.The performance-based approach could predict liquefaction hazard more accurately and conformably in various seismic regions than conventional procedures.The liquefaction hazard analysis for various assumed conditions of soil layers at sites located in Beijing area is performed by the procedure and the liquefaction hazard curves at these sites are respectively obtained.Based on a great deal of samples from the calculation and the conception of liquefied demand reference value of SPT,and influence coefficient of depth of soil layers and ground water levels,a simplified liquefaction hazard evaluation method in Beijing area is proposed.The method for estimating liquefaction hazard could also be established to other seismic regions.

关 键 词：基于性态地震工程 液化危险性 液化条件概率 液化安全系数 液化需求锤击数基准值 

分 类 号：TU375.4[建筑科学—结构工程]